During his first day on the stand, John Douglas Robinson claimed the man he’s accused of murdering had previously had sex with his girlfriend.

Robinson was the first witness called in the defence’s case Monday afternoon.

During the first day of the defence’s case, Robinson recalled a conversation with his now ex-girlfriend Gilbert about their sexual history. Robinson said Gilbert included Fair in the list of people she’d had sex with.

“It happened before I met her, prior to September 2007,” he told jurors in a soft-spoken tone.

The 46-year-old was not sure if a significant relationship had developed between Gilbert and Fair, nor did he know how many times the two had sex.

Robinson categorized Fair as an “acquaintance,” saying the two had similar friends and had conversations while drinking at a mutual friend’s house on two separate occasions. He was aware Fair and Gilbert remained friends, but Robinson had never hung out with him alone.

“If I saw him out and about it would be a ‘hi, bye’ and I’d keep on moving,” he said.

On September 27, 2008, the night of the alleged murder, Robinson said Fair came unannounced to the Princess Street apartment he shared with Gilbert.

He guessed Fair knocked on the upper door around 9 p.m.

Although he could only see his silhouette, Robinson knew right away it was Fair because of his height and ball cap.

“Cliff was holding the screen door open and we were pretty much face to face (when I got to the top of the stairs). Amy said something about having money for him and invited him in so he came trotting down the stairs,” Robinson said.

Robinson said Fair appeared disheveled and had already been drinking before he arrived.

“As soon as he stepped in the kitchen (I could see) he was a little big ragged. Maybe he was sleeping in his clothes. His face was a little puffy. It looked like maybe he had just woken up,” he said.

“I was a little on edge. I didn’t have any plans on having anyone over,” he said.

Before court proceedings were called for the day, jurors heard Robinson and Gilbert had about seven beers prior to Fair’s arrival. Gilbert had offered one of her beers to Fair.

Earlier in his testimony, Robinson outlined to jurors a life filled with excessive drinking and failed sobriety attempts.

Robinson told jurors, despite having no history of alcohol abuse in his family, he’d had a severe problem with drinking for decades. The problem was so severe he’d lost several jobs in his hometown of Halifax, N.S., before moving to Ontario in 1998.

After losing his job because his employer, a motor home dealership, went bankrupt, Robinson decided to move to Ontario with a friend and his family.

At the time he had no driver’s licence because of drunk driving charges he’d received while living out east.

They settled in Brantford because his friend had family there.

He did eventually get his licence back and started work as mechanic in Brantford.

Because there were four children at the home, Robinson was told by his friend not to come home drunk before they went to bed.

He broke that rule.

“He told me then to make a decision – either you’re not drinking and living here or you’re drinking and living somewhere else. So I did and quit drinking on the spot,” he said.

He maintained his sobriety for five years and four months after that, he said.

Robinson didn’t talk about why he started to drink again, but his fall off the wagon happened during his marriage to Sharon Ellery.

Ellery and Robinson remained close even after their marriage disintegrated. Ellery was called to the stand in mid-May to testify against her ex-husband. She told jurors Robinson confessed to the murder of Fair during a lengthy phone call November 8, 2008. Robinson has pleaded not guilty to the first-degree murder of 26-year-old Clifford Fair but pleaded guilty to offering an indignity to a dead body.

Robinson told jurors the biggest thing he and Gilbert had in common was alcohol. Each day, including the day of the alleged murder, the pair would split at least a case of beer.

Cassidy pleaded guilty in June 2009 to being an accessory to the alleged murder of Fair and was sentenced in September 2009 to a total of 31 months in prison.

Fair’s remains were discovered buried in the backyard of Robinson’s apartment in November 2008. The investigation into Fair's disappearance began on Oct. 18, 2008, when Pauline Fair, Clifford Fair's mother, reported to Woodstock police that her son was missing.